1. Field of the Invention
The present invention relates to an ignition apparatus including an ignition plug configured to ignite a combustible mixture in a combustion chamber of an internal combustion engine and an ignition control method for controlling the ignition apparatus.
2. Description of the Related Art
In recent years, there have been posed problems of environmental conservation and fuel exhaustion, and addressing those problems is an urgent matter in an automotive industry. Thus, as an example of the related art for addressing those problems, there is a technology of using exhaust gas recirculation (EGR) to reduce a pumping loss, to thereby drastically improve fuel efficiency.
However, burnt gas, which is exhaust gas, is large in heat capacity than the air, and hence when a large amount of the burnt gas is sucked again into the combustion chamber through the EGR, there is such a problem that an ignition property and a combustion property of the combustible mixture decrease. Thus, as an example of the related art for solving such a problem, there has been proposed an ignition apparatus in which an ignition plug is configured to generate a spark discharge larger in energy so as to stabilize the ignition property and the combustion property of the combustible mixture (for example, refer to Japanese Patent No. 5295305).
The ignition apparatus described in Japanese Patent No. 5295305 includes a first capacitor having a capacitance of 100 [μF] and a second capacitor having a capacitance of 5 [μF] so as to be able to generate a spark discharge large in energy. Moreover, the ignition apparatus is configured such that the voltage of the first capacitor becomes a higher voltage of 150 [V], and the voltage of the second capacitor becomes a higher voltage of 300 [V].
Here, when the ignition of the combustible mixture needs to be stopped, a defect caused by the capacitors occurs unless the ignition of the combustible mixture is stopped and the energies charged in the capacitors are discharged so as to decrease the voltages of the capacitors. For example, when a collision of a vehicle, on which such ignition apparatus described above is installed, is occurred with an object such as another vehicle, only the stop of the ignition of the combustible mixture is not sufficient, and when the voltages of the capacitors remain to be the higher voltages, for example, a short circuit of terminals may generate a spark as the defect caused by the capacitors.